Cellular Respiration Quiz Flashcards
(20 cards)
1
Q
Summary of Cellular Respiration
A
- The procells cells undergo to make ATP from glucose
- Release the energy of glucose by oxidizing glucose into CO2
2
Q
3 Pathways for Energy Release
A
Aerobic Respiration
Anaerobic Respiration
Fermentation
2
Q
Cellular Respiration Formula
A
Glucose + Oxygen –> Carbon Dioxide + Water + ATP
2
Q
Aerobic Cellular Respiration
A
- An oxidation reaction in which a series of enzymr-catalyzed reactions trnasfer electrons from high-energy molecules
- Mainly glucose to O2
- Releases energy in the form of ATP
- 5 main processes:
- Glycolysis, Krebs Cycle Prep, Krebs Cycle, Electron Transport System, Chemiosmosis
3
Q
Glycolysis
A
- To split GLUCOSE
- Occurs in the cytoplasm of cells
- Anaerobic process (without O2)- still part of aerobic
- Generates a samll amount of ATP and a molecule called PYRUVATE that has a large amount of chemical energy.
* PYRUVATE is the main goal of glycolysis
4
Q
Step-by-step Process of Glycolysis
A
- Glycolysis creates 2 molecules of Pyruvate
- The Goal is to make Pyruvate
- Glucose (6-carbon molecule) is split into two molecules of pyruvate (a 3-carbon molecule)
- 2 ATP molecules are used at the start of glycolysis- energy is needed to start the series of reactions
- NAD+ is reduced (GER) to NADH
- At the end, 4 molecules of ATP are produced and 2 molecules of pyruvate
- If oxygen is present, the pyruvate goes on to the Krebs Cycle, if oxygen is NOT present, the pyruvate goes on to fermentation
4
Q
Krebs Cycle Preparation
A
- A.K.A. Pyruvate Oxidation
- Before it enters the Krebs Cycle, pyruvate must undergo one reaction
- Pyruvate is a 3-carbon molecule
- It LOSES one carbon atom in the form of carbon dioxide (CO2)
- The other 2 carbon atoms are bonded to a molecule called Coenzyme A (CoA for short)- forming Acetyl-CoA
- NAD+ is reduced (GER) to NADH
5
Q
Krebs Cycle (Citric Acid Cycle)
A
- Happens in the mitochondrial matrix
- Acetyl CoA goes through a series of reactions that extract electrons & hydrogen ions
- Electrons & hydrogen ions are carried to an Electron Transport System (ETS)
- Carbon dioxide is released
6
Q
Steps of the Krebs Cycle
A
- Start with Acetyl CoA
- A 4-carbon molecule bonds with Acetyl CoA
- Results in a 6-Carbon molecule
- First CO2 is relased
- NAD+ is reduced (GER) to NADH
- A 5-carbon molecules is created after the 6-carbon molecule lost a carbon
- Second CO2 is released
- Another NAD+ is reduced to NADH
- ADP is converted into ATP
- A 4-carbon molecule resulted after the 5-carbon molecules lost a carbon
- FAD is reduced to FADH2 which is another energy carrier
- The 4-carbon molecule is converted to another 4-carbon molecule called Malate.
- NAD+ is reduced for the last time to NADH.
- Another 4-carbon molecule is created completing the cycle. It will join with Acetyl CoA to start the cycle again.
7
Q
Products From Krebs Cycle
A
- 3 molecule of NADH
- 1 molecule of FADH2
- 1 molecule of ATP
- Cycle goes through TWICE so:
6 molecules of NADH
2 molecuels of FADH2
2 molecules of ATP
8
Q
Electron Transport
A
- Simiilar to photosynthesis- high energy electrons are passed to a chain of electron-carrying molecules as they pass from one carrier to another, energy is released
- This is where most ATP is fromed
- Energy is used to pump hydrogen ions across the membrane from the mitpchondrial matris to the intermembrane space
- Build-up of ions in the intermembrane space creates a hydrogen ion concentration gradient
8
Q
Chemiosmosis
A
- Ions can diffuse back across the memrane but only through channels created by the enzyme ATP synthase.
- This enesyme uses the energy of the concentration graident to bind a phosphate group to ADP forming ATP
- This is called Chemiosmosis
8
Q
Final Electron Acceptor
A
- The final electron accpetor in the ETS is Oxygen
- Oxygen accepts electrons and hydrogen ions to make water
9
Q
Energy Balance Sheet
A
- Aerobic Cellular Respiration makes a total of 36 ATP
- ATP can be thought of as money for the cell, and ATP, FADH2, and NADH can be compared to different currencies
- GLYCOLYSIS: 2 ATP, 2 NADH (Behave like FADH2) Total ATP = 8 ATP
- PYRUVATE OXIDATION: 0 ATP, 2 NADH (Total ATP = 6 ATP
- KREBS CYCLE: 2 ATP, 6 NADH, 2 FADH2 (Total ATP = 22 ATP)
- ETC: 4 FADH2, 8 NADH
- Total ATP= 36 ATP
10
Q
Anaerobic Cellular Respiration
A
Cellular Respiration without oxygen
11
Q
2 Main Types of Anaerobic Cellular Respiration
A
- Alchol (Ethanol) Fermentation
- Lactic Acid Fermentation
11
Q
Alchol Fermentation & Lactic Acid Fermentation
A
- Both proccesses occur in the CYTOPLASM
- STAGES:
- Glycolysis- Identical 10-step process used in aerobic respiration (cellular respiration)
- Fermentation- Recycles the products of glycolysis in 2 different pathways, where either CO2 and ethanol (alcohol fermentation) or lactic acid (lactic acid fermentation) are the final waste products
12
Q
Alchol Fermentation
A
- The NADHs produced during glycolysis pass their hydrogen ions to acetraldehyde
- This forms ETHANOL
- EQUATION:
* Glucose + 2 ADP + 2Pi –> 2 Ethanol + 2CO2 + 2 ATP
13
Q
Purpose of Lactic Acid Fermentation
A
- Animals (Humans) will get ALL of their enery from aerobic respiration
- However, if a person is doing strnuous exercise the body CANNOT meet the energy demands of the muscle with just aerobic respiration
- Additional ATP can be made from lactic acid fermentation
14
Q
Lactic Acid Fermentation
A
- The NADH produced in glycolysis transfers its Hydrogen atoms to Pyruvate in the cytoplasm of the cell, regenerating NAD+ and allowing glycolysis to continue
- Results in a change of Pyruvate into Lactic Acid
-
OVERALL EQUATION:
- Glucose + 2ADP= 2Po –> 2Lactic Acid +2ATP
